Strut for automatic sprinkler-heads.



D. A. ALEXANDER.

STRUT FOR AUTOMATIC SPRINKLER HEADS.

APPLICATlON FILED JULY 13. 1917.

1,240,292, Patented Sept. 18, 1917.

lA/I/E/VTOR flam'd fl. Alexander ATTORNEY Q FKE DAVID A. ALEXANDER, OF ROCHESTER, NEW YORK.

STRUT FOR AUTOMATIC SPRINKLER-HEADS.

Specification of Letters Patent.

Patented Sept. 18, 1917.

Application filed July 13, 1917. Serial No. 180,267.

TQ all whom it may concern:

Be it known that I, DAVID A. ALEXANDER, a citizen of the United States, residing at Rochester, in the county of Monroe and State of New York, have invented a newand Improved Strut for Automatic Sprinkler-Heads, of which the following is a specification.

This invention relates to sprinklers of that class in which a valve is held in operative position against the water pressure thereon by means of a retaining member comprising suitable metal pieces secured to gether by soft solder adapted to melt or soften at a predetermined temperature which may be varied according to circumstances but which is well within the range of safety in order that when the temperature of the surrounding medium, usually air, rises above the predetermined point the solder is softened or melted sufficiently to permit the valve to open by arupture of the soldered union between the parts of the retaining member.

The objects of my invention are, first, to provide a valve holding member in the form of a strut the pressure upon which is in the nature .of a longitudinal thrust; second, to

construct such strut preferably of but two pieces of sheet metal thin enough to render them exceedingly sensitive to the action of heat and bearing one upon the other in a manner to hold the valve against all possible pressure with but a minimum amount of solder required to normally hold the pieces against separation; third, to provide a strut that may be placed in operative position with either end uppermost and that will buckle to one side or the other of its longitudinal center according to which end of the strut the solder first begins to melt; and, fourth, to provide a strut that will not only be quickly responsive but sure of separation once such separating action commences, thus overcoming any tendency of the strut to freeze as it is known in the art,-that is, the arresting of the separating action of the strutafter it has once started to open by a sudden chilling thereof by water escaping around the thus partly opened valve.

It is also desirable to accurately adjust the initial pressure upon the strut in order to insure accuracy and reliability of operation and to this end I prefer to make use of a sprinkler head permitting variable adjustment of such initial pressure.

With these objects in view my invention comprises the following described features as illustrated in the accompanying drawings, in which Figures 1 and 2 are face and side views, respectively, of the members for forming a strut in accordance with my preferred embodiment of the invention, such members being shown spaced from each other; Fig. 3 is a face view of a strut formed by members such as shown in Figs. 1 and 2; Fig. 4%, a side view of the strut seen in Fig. 3 but with the parts in the position they assume just after separating action commences; Fig. 5, a part front elevation and part vertical centralv sectional view of a sprinkler head provided with a strut such as seen in Fig. 8; Figs. 6 and 7 are views similar to Fig. 3 but showing modifications in construction of the strut members; Figs. 8 and 9, views similar to Fig. 1 of the members forming the struts seen in Figs. 6 and 7, respectively; Fig. 10 is a sectional view on the line 1010 of Fig. 6; Fig. 11, a side view of the strut shown in Fig. 7; and, Fig. 12, a perspective view of a strut made in accordance with my invention and provided with reinforcing plates soldered thereto.

Similar reference numerals refer to similar parts throughout the several views.

The sprinkler frame may be of any desired construction and of itself does not constitute any part of my invention. That shown in Fig. 5 comprises a cylindrical body member 2 having an externally threaded downward extension 3 for connection to a water supply pipe, a collar 4 threaded into the member 2, a diaphragm 5 seated against the undercut top of such collar, a diaphragm retaining ring 6, a head 7 connected to the collar 4 by the usual side arms 8, and a spreader 9 secured to such head. The valve proper is a hemispherical disk 10 seated in a centrally disposed opening in the diaphragm 5 and is provided with a recess to receive one end of the valveholding member or strut 12 the other end of which engages in a slot in the lower end of a bolt 13, such bolt being both prevented from rotation and held against longitudinal movement by apin 14 extending at right angles therethrough and through the head 7.

Refer to Figs. 1 to 4, inclusive.

The strut 12 is preferably of a regular com formation, as in Fig. 3, having parallel end edges of equal length and outwardly inclined side edges intersecting, preferably in a line 15 midway between the end edges and at right angles to the line of thrust. It is formed of two substantially similar flat pieces of metal 16 and 17 lying in the same plane and bearing one upon the other along such transverse center line. The length of the bearing is, preferably, the same as the width of the strut at the ends and the bearing portion of the member .16 is provided with a knife edge 18 adapted'toeng'age in a shallow groove 19 in the corresponding portion of the member 17, the sides of the groove being disposed at a greater angle to the vertical plane than those of the knife edge.

The member 16 has an extension 20 0 110116 side which with the main body portion of themember 17 forms the part of the strut to one side of the line 15, while the member 17 has a similar extension 21 which with the main body portion of the member 16'forms the part of the strut to the other side of the line 15. The outer ends of these extensions 20 and 21 are soldered to the members 17 and 16, respectively, such soldered unions being indicated at 22, 22 in Figs. 3 and 5. v I

The strut members 16 and 17 may, if de sired, be united by solder the entire length of their adjacent edges, but I have found that this is unnecessary and if solder, as at 22, is applied only at the outer ends of the extensions 20 and 21 the strut will hold up under the required thrust and willnot buckle until the solder has melted. The inner edges of the extension members 20 and 21 are cut away to provide clearance whereby the strut willmore readily separate and to prevent dirt accumulating along the bearing edges of the members 16 and 17 or corrosion of such parts the same may be covered with any suitable soft substance, not shown, such as beeswax. I

l/Vhen assembling the parts of the sprinkler the frame is supported by means of a suitable device, not shown, such as fingers engaging under the head 7 on each side of the longitudinal hole bored therein. The valve 10 is properly placed and the strut 12, the parts 16 and 17 thereof being united with solder, is then placed in its Position? that is, extendingin a median line between the valve and the bolt 13 with the free end of one of the parts thereof engaging in the depression therefor in the valve andthe corresponding end of the other one of such parts engaging in a slot in the lower end of the bolt 13.

A- constant and predetermined pressure is then brought to bear on the head of the bolt 13 and the thrust thus exerted is suson the valve will tendto compress the parts longitudinally but owing to the character of their bearing edges and the thinness of the metal such parts will buckle and force each other to one side or the other "of the median line, respective to the end of the strut at which separating action commences, and because of the small amount of solder required, due to the short length of the thus united edges, it will readily be seen'th'at the strut will not only be quickly responsive but absolutely certain of complete sep aration once such action commences. With the members 16 and 17 bearing directly against each other,e'nd to end, there can be no creeping action'which would tend to shorten thestrut and cause a leak around the valve.

Refer now to Figs. 6, 8 and 10. 1

A strut made in accordance with this modific'ation of my invention has the same general outline as that of the strut hereinbefore described. The -members thereof 23 and 24, howevendifi'er from the correspond ingmembers of the strut shown in Fig.

The members 23 and 24 he in the same plane with their inner, broken edges 25 and 26,

respectively, bearing against each "other on a line midwaybetweenthe ends of thestrut and at right angles to the line of thrust, and these engaging edges are formed'in the manner described with reference I to the edges 18 and 19 of the strut12. The member 23 is cutaway to receive a V-shap'ed "ex-- tensio'n-28 on the member 23. The two strut members are united by solder 33 at the outer ends of the extensions 27 and 28.

The strut shown in Figs. 7, 9 and 11 is similar in general characteristics to the other two already described but differs therefrom in that one of the members 2 9 is cut away to receive a centrally disposed extension 30 on the other member "31. The parts are united by solder at 32 and their inner edges bearone' against the other in-a line at right angles to the line of-thrust midway between the ends of the strut.

115 tension 27 on the member 24 and such latter member is cut away to receive a similar ex- If desired, thin reinforcing plates 34 may be soldered to the faces of the strut although they are not necessarily required, and a strut 35 provided with such feature is shown in perspective in Fig. 12.

What I claim is 1. In a sprinkler head of the character described having a valve and a thrust sustaining member, a valve holding member comprising a strut engaging and extending from end to end in a median line between the valve and the thrust sustaining member and formed of two plates lying in the same plane and having ends bearing one upon the other in a line at right angles to the line of thrust, one of such plates being cut away, to receive an extension on the other plate and the two plates being united by suitable solder along adjacent edges.

2. In a sprinkler head of the character described having a valve and a thrust sustaining member, a valve holding member comprising a strut engaging and extending from end to end in a median line between the valve and the thrust sustaining member and formed of two plates lying in the same plane and having ends bearing one upon the other in a line at right angles to the line of thrust and midway between the ends of the strut, one of such plates being cut away to receive an extension on the other plate and the two plates being united by suitable solder along adjacent edges.

3. In a sprinkler head of the character described having a valve and a thrust sustaining member, a valve holding member comprising a strut engaging and extending from end to end in a median line between the valve and the thrust sustaining member and formed of two plates lying in the same plane and having ends bearing one upon the other in a line at right angles to the line of thrust, the said bearing end of one plate having a knife edge engaging in a groove in that of the other plate, one of such plates being cut away to receive an extension on the other plate and the two plates being united by suitable solder along adjacent edges.

l. In a sprinkler head of the character Copies of this patent may be obtained for five cents each, by addressing the described having a valve and a thrust sustaining member, a Valve holding member comprising a strut engaging and extending from end to end in a median line between the valve and the thrust sustaining member and formed of two plates lying in the same plane and having ends bearing one upon the other in a line at right angles to the line of thrust, each of such plates being cut away to receive an extension on the other plate and the two plates being united by suitable solder along the edges of said extension.

5. In a sprinkler head of the character described having a valve and a thrust sustaining member, a valve holding member comprising a strut engaging and extending from end to end in a median line between the valve and the thrust sustaining member and formed of two plates lying in the same plane and having end portions bearing one upon the other in a line at right angles to the line of thrust, one of such plates being cut away on one side to receive an extension on the other plate and such second named plate being cut away on the opposite side to receive an extension on the first named plate, the two platesbeing united by suitable solder along the edges of said extensions.

6. In a sprinkler head of the character described having a valve and a thrust sustaining member, a valve holding member comprising a strut engaging and extending from end to end in a median line between the valve and the thrust sustaining member and formed of two plates lying in the same plane and having end portions bearing one upon the other in a line at right angles to the line of thrust and midway between the ends of the strut, the said bearing portion of one plate having a knife edge engaging in a groove in that of the other plate, one of such plates being cut away on one side to receive an extension on the other plate and such second named plate being cut away on the opposite side to receive a similar extension on the first named plate, the two plates being united by suitable solder along the edges of said extensions.

DAVID A. ALEXANDER.

Commissioner of Patents,

Washington, D. 0. 

